The mass spectral fragmentation of 9alpha-hydroxy steroids and related compounds.

The fragmentation processes occurring in various 9alpha-hydroxy steroids upon electron ionization have been studied. The mechanisms proposed for the formation of the prominent ions in these spectra have been confirmed with the aid of deuterium labelling, measurements on metastable ion decompositions, low eV spectra and high resolution mass measurements. The fragmentation of the corresponding 9-oxo-9,10-seco steroids, which shows analogy to that of the 9alpha-hydroxy compounds in many respects, has also been discussed.